ITU-R Recommendation BT.2100, more commonly known by the abbreviations Rec. 2100 or BT.2100, introduced high-dynamic-range television (HDR-TV) by recommending the use of the perceptual quantizer (PQ [SMPTE ST 2084]) or hybrid log–gamma (HLG) transfer functions instead of the traditional "gamma" previously used for SDR-TV.[1][2]
It defines various aspects of HDR-TV such as display resolution (HDTV and UHDTV), frame rate, chroma subsampling, bit depth, color space, color primaries, white point, and transfer function.[3][4] It was posted on the International Telecommunication Union (ITU) website on July 4, 2016.[3][4] Rec. 2100 uses a wide color gamut (WCG) which is the same as Rec. 2020's.[4]